I recently ran into an issue where Photoshop was freezing (http://forums.adobe.com/thread/1214524 - my issue starts at reply #4) and in order to solve it, I had to open Photoshop by pressing CTRL + ALT + SHIFT, which deletes all preferences. Now that I can open Photoshop, I can't toggle into the different screen modes. The F key doesn't do anything anymore and the options on the toolbar are disabled. I can only choose Standard Screen mode.

What's wrong and how can I fix this so I can work in full-screen mode again? I am on a MacBook Pro using the latest version of Photoshop CS6 from Creative Cloud.

I had to open Photoshop by pressing CTRL + ALT + SHIFT, which deletes all preferences.

I am on a MacBook Pro using the latest version of Photoshop CS6 from Creative Cloud.

The above resets the preferences for a Windows OS computer, not sure what it does on a Mac. For a Mac if you want to reset preferences start PS and immediately hold down Cmd + Option + shift. You should get a reset window.